Money has looked very different in different ages. What was treated as a valued object early on was the cowrie, then came coins cast in bronze, and later silver weighed out. With each change, the thing people used to measure value in buying and selling changed too.
Large numbers of cowries and imitation cowries have been found at Shang sites such as Yinxu, which shows that the cowrie, as a prized valuable, already had the beginnings of a role as a medium of exchange.
After the Qin unified the realm, it standardised the coinage on the round, square-holed banliang. This round coin with a square hole kept its form for two thousand years.
In 1581 (Wanli 9), Zhang Juzheng extended the Single Whip reform, commuting taxes and labour service into payments in silver, and silver became the main means of payment of the state.
Currency Evolution is the class in the chapter on Commerce on the succession of money from the Shang to today: from the cowries found at Shang sites, to the round, square-holed banliang coin after the Qin unification, to the payment mainly in silver of the Ming and Qing. The right to cast coin and the standard of its fineness were held by the successive dynasties.
